Install Mode: 32-bit vs. 64-bit

An installation can run in one of two modes: 32-bit or 64-bit.

64-bit mode is selected if the user is running a 64-bit version of Windows and the system's processor architecture is included in the value of the ArchitecturesInstallIn64BitMode [Setup] section directive. Otherwise, 32-bit mode is used.

How do the two modes of installation differ? Primarily, the differences lie in where things are installed by default.

In 32-bit mode:

In 64-bit mode: